c++ - Issues in searching through the vector? -

There is a vector in the form given to me (C ++):

  Vector & lt; Pair of & lt; Integer, integer & gt; & Gt; U;   
 Now when the first element of u.first gets equal to 12 then I want to break with the loop. I am using the following code for this:  
  while (1) {if ((search (u.begin) first, u.end (). First, 12)! = U.end ().)) {Break; }}   
 However, it gives me an error  
  'Unable to resolve the identifier first'    
 
 
  std :: find  iterates on a category and returns an iterator to the first element in the sequence which matches The provided value ( 12 , in your case), Iterators are not elements in the container, they are pseudo-references to the elements in the container.  
 In order to achieve the element you have to specify an error. Therefore,  u.begin () - & gt; First  will be the  first  value of the initial element of the container  u.begin (). First  is unnecessary.  
 In any case, to find a matching element using an operation other than  == , you use  find_if  with a custom suspect For example, using the Lambda expression:  
  Automatically interstate (std :: find_if (u.begin (), u.end (), [] (std :: Pair & lt; int, int & gt; bracket & v) {return v.first == 12;})); If (this! = U.end ()) continues;